As a main cause for a deterioration in the picture quality of a solid-state image pickup device, for example, there is known a noise generated every horizontal line (row), that is, a so-called transverse stripe noise. The transverse stripe noise is mainly generated in reset when a reading operation for each horizontal line is carried out. Moreover, some solid-state image pickup devices serve to subtract an average for each line of an OB signal sent from a horizontal optical black unit (OB unit) every horizontal line of an image sensor. The solid-state image pickup devices can effectively remove a noise generated on the same level in an effective pixel unit and the horizontal OB unit in an image sensor and can regulate a black level of the effective pixel signal into the level of the OB signal.
On the other hand, in the case in which noises having different levels are generated in the effective pixel unit and the horizontal OB unit, the subtraction processing reduces precision in a noise reduction, and furthermore, influences a black level regulation. In this case, the solid-state image pickup device can make, as an alternative, processing for using a vertical OB unit in place of the horizontal OB unit, for example. In the case in which such alternative means is not present, however, the solid-state image pickup device carries out processing for using the horizontal OB unit while taking such a risk that the black level regulation is adversely affected. Alternatively, the solid-state image pickup device uniformly stops noise reduction processing and carries out the black level regulation into a certain level which is preset. Thus, the solid-stage image pickup device carries out useless processing due to a structure for reducing a noise in the black level regulation in some cases. Consequently, it is hard to execute effective noise reduction processing.